One popular application for the Tesira EX-LOGIC is to interface with conferencing microphones that feature mute switches and LED indicators. This article describes how to physically connect a beyerdynamic vertical array microphone to a Tesira EX-LOGIC expander.
After completing the steps in this article, you will be able to connect a beyerdynamic RM 31 RC microphone to a Tesira EX-LOGIC. This will allow your Tesira configuration to mute and unmute the connected microphone remotely and it will also allow the switch on the microphone to control functions within your Tesira configuration (like camera control or override/priority logic functions).
The microphone uses phantom power to power its LED and logic circuit, so no external power supply is required.
The RM 31 RC microphone facilitates a mute switch and a single-color LED. It comes with a 5-pin XLR connector, with the following functions assigned to each pin:
|Pin 1 (br)||Ground|
|Pin 2 (rd)||Audio (+)|
|Pin 3 (bl)||Audio (-)|
|Pin 4 (wh)||Switch output|
|Pin 5 (bk)||LED input|
An EX-LOGIC has 16 Logic I/O connections. Each Logic I/O can either be used as an input or an output (but not both), and input/output status of each terminal is determined by the Tesira programming. The diagrams in this article arbitrarily show logic inputs as channels 1-8, and logic outputs as channels 9-16, but the Tesira programming can define the inputs and outputs differently.
The diagram below shows how to connect a beyerdynamic RM 31 RC boundary microphone with a 5-pin XLR to an EX-LOGIC.
The desired operation mode is set by the rotary switch recessed inside the microphone base. The hexadecimal switch allows for 16 different operational modes:
• Position PTT: The microphone is switched on as long as the button is pressed.
• Position PTM: The microphone is switched off as long as the button is pressed (cough button).
• Disabled (ON): The Microphone can now be operated via external logic, only.
• Position ON/OFF: The microphone is switched on or off by pressing the push button on the microphone.
In all positions the LED indicates the activation of the microphone.
Note that the internal microphone signal flow cannot be bypassed. A mute condition triggered from internal or external operation, will always interrupt the audio signal flow. This should be considered in applications with Gating Auto Mixers and Acoustic Echo Cancelling inputs.